Dose and frequency dependent effects of olive mill wastewater treatment on the chemical and microbial properties of soil

Olive mill wastewater (OMW) is a problematic by-product of olive oil production. While its high organic load and polyphenol concentrations are associated with troublesome environmental effects, its rich mineral and organic matter contents represent valuable nutrients. This study aimed to investigate the valorization of this waste biomass as a potential soil conditioner and fertilizer in agriculture. OMW was assayed at three doses 50, 100, and 200 m³ ha⁻¹ year⁻¹) over three successive years in olive fields. The effects of the effluent on the physico-chemical and microbial properties of soil-layers were assessed. The findings revealed that the pH of the soil decreased but electrical conductivity and organic matter, total nitrogen, sodium, and potassium soil contents increased in proportion with OMW concentration and frequency of application. While no variations were observed in phosphorus content, slow increases were recorded in calcium and magnesium soil contents. Compared to their control soil counterparts, aerobic bacteria and fungi increased in proportion with OMW spreading rates. The models expressing the correlation between progress parameters and OMW doses were fitted into a second degree polynomial model. Principal component analysis showed a strong correlation between soil mineral elements and microorganisms. These parameters were not related to phosphorus and pH.     

Effects of dietary cadmium exposure on osmoregulation and urine concentration mechanisms of the semi-desert rodent Meriones shawi

Contamination by cadmium in the environment is of great concern because of its toxicity and threats to human and animal health. The current study was conducted to investigate the effects of a cadmium contaminated diet on the osmoregulation and urine concentration mechanisms of the semi-desert rodent Meriones shawi and eventual accumulation of this metal in vital organs such as the kidneys, which are directly implicated in water regulation. Originally, we used Differential Pulse Anodic Stripping Voltammetry (DPASV) to avoid the matrix interference due to the highly organic content in the biological samples. Our results show that Meriones shawi successfully maintained a homeostasis state and presented a special adaptation to regulate urine volume during cadmium exposure by decreasing diuresis and increasing urinary osmolality. The plasma osmolality and hematocrit remained constant throughout the experiment. The stripping signals of cadmium are linear up to 0.3-100 μg L(-1) range, with a detection limit of 0.28 μg L(-1). The DPASV technique was useful for easy, fast, selective and sensitive determination of Cd, which permits working at cellular concentration. This gives us more information about the chemical form in which Cd is introduced into the organ, as well as the intracellular Cd quantities. This study has potential importance if this valuable novel animal model, imitating human and animal environmental chronic exposure to Cd, could serve as an appropriate terrestrial biomonitor for Cd contaminated sites. These results are encouraging in the context of developing a low-cost and fast technology for the detection of pollutants and for studying the impairment caused by their effects.     

Soil erosion and sediment fluxes analysis: a watershed study of the Ni Reservoir,Spotsylvania County,VA, USA

Anthropogenic forces that alter the physical landscape are known to cause significant soil erosion, which has negative impact on surface water bodies, such as rivers, lakes/reservoirs, and coastal zones, and thus sediment control has become one of the central aspects of catchment management planning. The revised universal soil loss equation empirical model, erosion pins, and isotopic sediment core analyses were used to evaluate watershed erosion, stream bank erosion, and reservoir sediment accumulation rates for Ni Reservoir, in central Virginia. Land-use and land cover seems to be dominant control in watershed soil erosion, with barren land and human-disturbed areas contributing the most sediment, and forest and herbaceous areas contributing the least. Results show a 7 % increase in human development from 2001 (14 %) to 2009 (21.6 %), corresponding to an increase in soil loss of 0.82 Mg ha^-1 year^-1 in the same time period. ²¹⁰Pb-based sediment accumulation rates at three locations in Ni Reservoir were 1.020, 0.364, and 0.543 g cm^-2 year^-1 respectively, indicating that sediment accumulation and distribution in the reservoir is influenced by reservoir configuration and significant contributions from bedload. All three locations indicate an increase in modern sediment accumulation rates. Erosion pin results show variability in stream bank erosion with values ranging from 4.7 to 11.3 cm year^-1. These results indicate that urban growth and the decline in vegetative cover has increased sediment fluxes from the watershed and poses a significant threat to the long-term sustainability of the Ni Reservoir as urbanization continues to increase.     

Implications of differing input data sources and approaches upon forest carbon stock estimation

Site index is an important forest inventory attribute that relates productivity and growth expectation of forests over time. In forest inventory programs, site index is used in conjunction with other forest inventory attributes (i.e., height, age) for the estimation of stand volume. In turn, stand volumes are used to estimate biomass (and biomass components) and enable conversion to carbon. In this research, we explore the implications and consequences of different estimates of site index on carbon stock characterization for a 2,500-ha Douglas-fir-dominated landscape located on Eastern Vancouver Island, British Columbia, Canada. We compared site index estimates from an existing forest inventory to estimates generated from a combination of forest inventory and light detection and ranging (LIDAR)-derived attributes and then examined the resultant differences in biomass estimates generated from a carbon budget model (Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3)). Significant differences were found between the original and LIDAR-derived site indices for all species types and for the resulting 5-m site classes (p?<?0.001). The LIDAR-derived site class was greater than the original site class for 42% of stands; however, 77% of stands were within ±1 site class of the original class. Differences in biomass estimates between the model scenarios were significant for both total stand biomass and biomass per hectare (p?<?0.001); differences for Douglas-fir-dominated stands (representing 85% of all stands) were not significant (p?=?0.288). Overall, the relationship between the two biomass estimates was strong (R ²?=?0.92, p?<?0.001), suggesting that in certain circumstances, LIDAR may have a role to play in site index estimation and biomass mapping.     

Dynamic extreme values modeling and monitoring by means of sea shores water quality biomarkers and valvometry

Water quality can be evaluated using biomarkers such as tissular enzymatic activities of endemic species. Measurement of molluscs bivalves activity at high frequency (e.g., valvometry) during a long time period is another way to record the animal behavior and to evaluate perturbations of the water quality in real time. As the pollution affects the activity of oysters, we consider the valves opening and closing velocities to monitor the water quality assessment. We propose to model the huge volume of velocity data collected in the framework of valvometry using a new nonparametric extreme values statistical model. The objective is to estimate the tail probabilities and the extreme quantiles of the distribution of valve closing velocity. The tail of the distribution function of valve closing velocity is modeled by a Pareto distribution with parameter ??_t,τ, beyond a threshold τ according to the time t of the experiment. Our modeling approach reveals the dependence between the specific activity of two enzymatic biomarkers (Glutathione-S-transferase and acetylcholinesterase) and the continuous recording of oyster valve velocity, proving the suitability of this tool for water quality assessment. Thus, valvometry allows in real-time in situ analysis of the bivalves behavior and appears as an effective early warning tool in ecological risk assessment and marine environment monitoring.     

An agenda for assessing and improving conservation impacts of sustainability standards in tropical agriculture

Sustainability standards and certification serve to differentiate and provide market recognition to goods produced in accordance with social and environmental good practices, typically including practices to protect biodiversity. Such standards have seen rapid growth, including in tropical agricultural commodities such as cocoa, coffee, palm oil, soybeans, and tea. Given the role of sustainability standards in influencing land use in hotspots of biodiversity, deforestation, and agricultural intensification, much could be gained from efforts to evaluate and increase the conservation payoff of these schemes. To this end, we devised a systematic approach for monitoring and evaluating the conservation impacts of agricultural sustainability standards and for using the resulting evidence to improve the effectiveness of such standards over time. The approach is oriented around a set of hypotheses and corresponding research questions about how sustainability standards are predicted to deliver conservation benefits. These questions are addressed through data from multiple sources, including basic common information from certification audits; field monitoring of environmental outcomes at a sample of certified sites; and rigorous impact assessment research based on experimental or quasi‐experimental methods. Integration of these sources can generate time‐series data that are comparable across sites and regions and provide detailed portraits of the effects of sustainability standards. To implement this approach, we propose new collaborations between the conservation research community and the sustainability standards community to develop common indicators and monitoring protocols, foster data sharing and synthesis, and link research and practice more effectively. As the role of sustainability standards in tropical land‐use governance continues to evolve, robust evidence on the factors contributing to effectiveness can help to ensure that such standards are designed and implemented to maximize benefits for biodiversity conservation.     

Distribution and assessment of heavy metal toxicity in sediment cores from Bizerte Lagoon,Tunisia

To examine the state of pollution of Bizerte Lagoon which is exposed to intense anthropogenic pressure, two sediment cores were taken at two sites, one undergoes the dual effects of both marine waters arriving from the Mediterranean Sea through the Channel, and also of freshwater from the Tinja River; the other core is located at the center of the lagoon where water depth is maximal (12 m). Heavy metal concentrations in the two cores were assessed, with calculated enrichment factors and geo-accumulation indexes. Core sediments were also studied for chemical speciation and their monosulfide contents were measured. Results from enrichment factors and geo-accumulation indexes show an accumulation of Cd, Zn, Cr, and Pb, while chemical speciation revealed a risk only from Cd and Mn. Comparison of sequential extraction values with those of acid volatile sulfides revealed that non-toxic effects may be caused by any of the studied metals in the sediment.     

鄱阳湖区国土资源综合评价和开发整治战略

本文在鄱阳湖区国土资源综合评价的基础上,提出了开发整治的战略。鄱阳湖区自然资源比较丰富,开发潜力大。但是,由于洪涝干旱等自然灾害比较频繁,经济结构不合理,商品生产不发达,人口增长率高,科技文化比较落后,环境恶化等原因,影响了湖区经济的发展。为了开发整治鄱阳湖区,本文提出了整治洪涝灾害,充分发挥湖泊水资源优势;优化经济和产业结构,合理利用国土资源,充分发挥湖区农业优势;严格控制人口增长,增加智力投资,提高人口素质,促进科技进步等战略问题。     

城市道路交通噪声评价方法研究进展

在分析城市道路交通噪声现状的主要危害的基础上，较全面介绍了国内外城市道路交通噪声评价方法的最新进展。继而分析了评价方面存在的问题，并讨论了这一环境声学领域未来发展方向。